Operating Instructions

Chapter 4 - Parameters and Menu Structure
I/O and Hardware (M5)
157 | 187
Siemens Industry, Inc.
Siemens BT300 HVAC Drive
DPD01809
Smart Infrastructure
2019-05-29
No. of registers HI
00 hex Invalid number of registers 0005 hex (= 5)
No. of registers LO
05 hex
ERROR
CRC HI
34 hex
CHECK
CRC LO
66 hex CRC field 3466 hex (= 13414)
Message frame:
01
04
17
70
00
05
34
66
Exception Response:
Answer Slave - Master:
ADDRESS
01 hex Slave address 1 hex (= 1)
FUNCTION
84 hex Most significant bit set to 1
ERROR CODE
04 hex Error code 04 => Slave Device Failure
ERROR CRC HI
42 hex CRC field 42C3 hex (= 17091)
CHECK CRC LO
C3 hex
Reply frame:
01
84
04
42
C3
Quick Setup
For monitoring of objects using ModBus RTU complete the following steps:
1. Select:
Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > Common settings (M5.8.1) >
Protocol >Edit.
2. Select ModBus RTU.
3. Select:
Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > ModBus RTU (M5.8.3) > Parameters
(M5.8.3.1) > Slave Address (M5.8.3.1.1) > Edit.
4. Enter desired address.
5. Select:
Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > ModBus RTU (M5.8.3) > Parameters
(M5.8.3.1) > Baud Rate (M5.8.3.1.2) > Edit.
6. Select desired baud rate.
7. Select:
Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > ModBus RTU (M5.8.3) > Parameters
(M5.8.3.1) > Parity Type (M5.8.3.1.3) > Edit.
8. Select desired parity type.